Generally, in a mobile communication system supporting BCMC, since multimedia data such as audio and video should be transmitted, a high data rate is required. So, in order to perform a broadcast/multicast (hereinafter abbreviated BCMC) service, a packet data channel of a physical layer needs to support a high data rate. In a current mobile communication system, BCMC data transported via packet data channels of a previously existing physical layer.
If contents to be broadcast are generated from a base station or forwarded to the base station from another place, the base station transmits the contents to a radio channel using a protocol negotiated between the base station and a mobile subscriber station to enable a plurality of users within the base station area to view or listen to the contents.
For instance, messages exchanged for BCMC service execution between a base station and mobile subscriber stations include a broadcast overhead message, a broadcast registration message and a broadcast reject message.
The broadcast overhead message is a message that is transmitted in common to mobile subscriber stations from a base station. And, the broadcast overhead message contains information enabling a corresponding mobile subscriber station to stably receive a packet data channel or a broadcast channel and to perform decoding. For instance, the information transmitted via the broadcast overhead message includes information for contents of a BCMC service, information for a channel used for BCMC, mobile subscriber station registration information and the like. These informations are periodically transmitted via the broadcast overhead message and the mobile subscriber station receiving the BCMC service should receive the broadcast overhead message.
The broadcast registration message is a message transmitted from a mobile subscriber station to a base station. And, the broadcast registration message carries information for a BCMC service flow to be received by a mobile subscriber station to a base station. And, the broadcast reject message is a message transmitted to a mobile subscriber station from a network in response to the broadcast registration message. The broadcast reject message contains information for a service-rejected BCMC flow among a plurality of BCMCS flows requested using the broadcast registration message. Meanwhile, information indicating that services of all BCMCS flows requested by a mobile subscriber station are allowed can be transmitted through a specific field value of the broadcast reject message.
Each of the broadcast overhead message, the broadcast registration message and the broadcast reject message includes FlowDiscriminatorCount field. One BCMC service flow has at least one BCMCS configuration component flow. And, the FlowDiscriminatorCount field contains information for a number of BCMCS configuration component flows configuring one BCMC service.
And, each of the broadcast overhead message, the broadcast registration message and the broadcast reject message includes BCMCSFlowDiscriminator field for discriminating a BCMC component flow.
However, since a value of the FlowDiscriminatorCount field indicating information for the BCMCS flow number is fixed to 6 bits, it is unable to transmit the information for the BCMC component flow efficiently.